/*
 *   Licensed to the Apache Software Foundation (ASF) under one
 *   or more contributor license agreements.  See the NOTICE file
 *   distributed with this work for additional information
 *   regarding copyright ownership.  The ASF licenses this file
 *   to you under the Apache License, Version 2.0 (the
 *   "License"); you may not use this file except in compliance
 *   with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing,
 *   software distributed under the License is distributed on an
 *   "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *   KIND, either express or implied.  See the License for the
 *   specific language governing permissions and limitations
 *   under the License.
 *
 */
package com.bkbw.live.battle.net.codec;

import org.apache.mina.filter.codec.ProtocolEncoderOutput;
import org.apache.mina.filter.codec.ProtocolEncoderAdapter;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.example.imagine.step1.ImageResponse;

import javax.imageio.ImageIO;

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.lang.reflect.Method;

/**
 * an encoder for {@link ImageResponse} objects 
 *
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 */
public class NetResponseEncoder extends ProtocolEncoderAdapter {

    public void encode(IoSession session, Object message, ProtocolEncoderOutput out) throws Exception {
	  	Class c = message.getClass();
	  	Method m1 = c.getMethod("getSerializedSize",null);
	  	int messageSize = (Integer) m1.invoke(message, null);
        int capacity = messageSize + 6;//4用于写入包长  2用于写入消息头
        IoBuffer buffer = IoBuffer.allocate(capacity, false);
        //写入包长+2的原因是有2个字节的消息头
        buffer.putInt(messageSize+2);
        //写入消息头
        short head = PackageHead.getHeadByClassName(c.getName());
        if (head == 0) {
        	System.out.println("head 0");
        }
        buffer.putShort(head);
        //System.out.println("发出消息"+head+":"+c.getName());
        //序列化后写入包体
        ByteArrayOutputStream baos = new ByteArrayOutputStream();  
        com.google.protobuf.CodedOutputStream cos = com.google.protobuf.CodedOutputStream.newInstance(baos); 
      
        Method m2 = c.getMethod("writeTo",com.google.protobuf.CodedOutputStream.class);
        m2.invoke(message, cos);

        cos.flush();
        buffer.put(baos.toByteArray());
        buffer.flip();
        out.write(buffer);
    }

}
